The present invention relates to an electronic apparatus for cooling a semiconductor element therein, with using a liquid cooling system.
The semiconductor element generates heat during the operation thereof, which is used in an electronic apparatus, such as a computer, etc.
In particular, with the semiconductor in recent year, the heat-generation comes up much more, due to the demands on high processing speed and high capacity or performances thereof. In general, the semiconductor element looses the function of as the semiconductor element, remarkably, when exceeding over a predetermined level in temperature thereof, and therefore it is necessary to make compulsive cooling, in particular, on the semiconductor having a large amount of heat generation thereof.
As a method for cooling down the semiconductor of the electronic apparatus, for example, there are already known methods of applying the heat conduction, applying an air cooling, with using a heat pipe, and applying a liquid cooling, etc.
Among of those, cooling applying a liquid cooling is most effective for the semiconductor element having large heat-generation.
Such the cooling method applying the liquid cooling is described, in more details thereof, for example, Japanese Patent Laying-Open Nos. Hei 5-335454 (1993), Hei 6-97338 (1994), Hei 6-125188 (1994), Hei 10-213370 (1998), etc.
However, those conventional technologies are limited in the use thereof only in a filed of a large-scaled computer.
This is because the liquid cooling system comes to be large in the scale due to the fact that it needs a large number of parts for exclusive use of cooling, such as a pump, a piping system, a radiator, etc., and it is difficult to maintain the reliability in respect of applying the liquid into cooling thereof.
Also, another one reason thereof is the fact that such the semiconductor element is not used in the field other than the large-scaled computer, which has a large heat-generation so that the liquid cooling is needed therein.
Technology of applying the liquid cooling into a small-sized electronic apparatus is disclosed in Japanese Patent Laying-Open No. Hei 6-266474 (1994). In this prior art, a heat-receiving jacket attached on the semiconductor element and a radiator disposed apart from it are connected through flexible tubes, thereby cooling down it with an aid of the liquid flowing therein.
However, as was mentioned previously, an amount of heat-generation comes up every year, in particular, of the semiconductor elements, etc., which are used in the electronic apparatuses, such as, a personal computer, a home server, a projector, a media storage, etc., and for treating with it, but a compulsive cooling is not sufficient enough, with using the natural air cooling or a fan, or a cooling of using the heat pipe therein.
Then, attention was paid onto the technology described in Japanese Patent Laying-open No. Hei 6-6266474 (1994), and with this, it is possible to receive the liquid cooling system within an inside of a case of a personal computer, by using the case itself of the computer to be a heat radiation plate, which is made of a metal material having good heat conductivity.
However, installation of the liquid cooling system into such the computer causes a new problem.
That is, due to the fact that only a small amount of the liquid is held within the liquid cooling system, and further that the operating temperature thereof is relatively high, etc., corrosion is promoted on the parts or elements in contact with the liquid, which are made of a metal material, such as, the heat-receiving jacket and the radiator, since the liquid is degraded in quality thereof even if the corrosive ion flow out in a very small amount thereof, in particular, from the parts or element of an organic material (i.e., the parts or element made of synthetic resin).
If causing water leakage due to the corrosion, it results into an important problem of stopping the function of that electronic apparatus; therefore, it is indispensable to make a treatment of measure of anti-corrosion on the parts or element, to be in contact with the cooling water.
Further, a treatment of measure of anti-corrosion due to a liquid is already known, for example, in Japanese Patent Laying-Open No. 2003-185321 (2003).